Inflatable drain plug



FIG. 1: Top right perspective view;

FIG. 2: Left end view;

FIG. 3: Right end view;

FIG. 4 is a top plan view;

FIG. 5 is a bottom plan view;

FIG. 6 is a right side elevation; and,

FIG. 7 is a left side elevation.

The broken line showing is included for the purpose of illustrating portions of the article that form no part of the claimed design. 

The ornamental design for an inflatable drain plug, as shown and described. 